Safety apparatus for boilers



March 4, 1941. A. e. BLANCHARD 2,233,395

SAFETY APPARATUS FOR BOiLERS Filed Oct. 14, 1935 5 SheetsSheet 1 Gfilanck ard March 1941-v A. QBLANcI-IARD 2 95 SAFETY APPARATUS FOR BOILERSFiled Oct. 14, 1935 5 Sheets-Shet 2 jww. Z 25 7] EJMEIMW March 1941. A.G. BLANCHARD 33.395

SAFETY APPARATUS FOR BOILERS Filed Oct. 14, 1935 5 Sheets- Sheet 3 fi gig 42 nadazw 911s Snow ms March 4, 19 A. a. BLANCHARD 2,233,395

I v SAFETY APPARATUS FOR BOILERS Filed Oct. 14, 1935 s Sheets-Shet 4'lmi WT ,w

NHL Q} 76 I lllllll mm Mar 4, 1941 I A. G. BLANCHARD 3 9 SAFETYAPPARATUS FOR BOILERS Filed Oct. 14, 1935 5 Sheets-Sheet 5 Patented Mar.4, 1941 UNITED STATES PATENT ()FFICE 1 2,233,395 1 SAFETY ArrAaA'rUs FORBOILERS Alva G. Blanchard, Shreveport, La. Application October- 14',1935, Serial No. 44,988

'oleims. (or! 122-504) This invention relates to improvements in safetydevices for boilers.

One object of the invention is to provide auto matic means formaintaining the water level in boilers within certain specified maximumand minimum limits. Another object is to provide automatic means forgiving a warning signal to the boiler attendant or fireman in the eventthe automatic vice comprising automatically operated means for cuttingoff the fuel supply (to gas-fired boilers) in case the warning signaland the water supply, Where both of the latter are automaticallycontrolled, should become inoperable, or if the signal should bedisregarded by the attendant, these automatic fuel cut-off means beingoperable at a time when the Water level has receded to a dangerously lowpoint.

A still further object is to provide means for regulating the operationof any or all of the safety devices, above mentioned, i. e., the watersupply; the fuel supply; and the signal, by means responsive tovariations in the water level in the boiler. More specifically, thisfeature of the invention comprises a master control unit adapted tocontain a body of fluid whose surface corresponds to the water level inthe boiler and in which there is supported a float for controlling theoperation of the safety devices above mentioned.

Another object is the provision of a safety apparatus for boilerswherein the safety devices are actuated by fluid pressure, preferably bsteam from the boiler itself. t

Still another object is the provision of means in a safety apparatus ofthis character wherein the successive operation of the various safetydevices can be timed and varied at will.

Another object contemplates the provision of a novel assembly and methodof assembly of certain of the structural parts of the apparatus,

such as the valve seats in the ports of the'master'u'nit and "themounting of the valves for said seats, whereby the assembly, retention'and ex traction of certain structural elements are greatly facilitated:

With these and other obiectsin view, .the in In. the accompanyingdrawings illustrating. ,v a

preferredembodiment of the invention- Figure 1 isan elevational viewillustrating,

more or less diagrammatically, a boiler with the master control unit,the warning signal device. and the connections for controlling thevalves of the fuel and water supply conduits;

Fig.2 is a horizontal sectional view through the float-operated mastercontrol unit, illustrating the master control valves and seats therefor;

Fig. 3 is a vertical sectional view through the master control unit, butillustrating a modified form of valve seat construction:

Fig. 4 is a transverse vertical section on the line 4-4 of Fig. 3;

Fig. 5 is a vertical sectional view through the control valve for thewater supply conduit of the boiler;

Fig. 6 is a vertical sectional view through the fuel cut-off valve ofthe fuel supply conduit;

Figs. 7A and 7B are vertical sectional views illustrating, more or lessdiagrammatically, the

assembly and extraction of the pin which carfor the, control valves ofthe master control unit.

. The boiler I0, illustrated more or less diagrammatically in Fig. 1,has associated therewith themaster control unit I00, the upper portionof said unit being connected by a pipe IOI to the steam chamber of theboiler and by pipe I02 to the water chamber of the boiler. Connected tosaid master control unit I00, by means to be more specifically describedhereinafter, is a warning signal, preferably an audible signal in theform of a whistle 26; a valve-actuating mechanism 20 for operating avalve in thefuel supply conduit 20a; and a valve-operating mechanism 40for the valve in water supply line 40a. It will be understood this fuelcontrol means is applicable only to boiler constructions wherein gas isused as fuel. It will also be appreciated that, while the level of thewater in the boiler is to-be controlled through the watersupply conduit40a, other means may be utilized for initially supplying water totheboiler or, if desired, a by-pass 401) having a manually controlledvalve 40c'therein may be provided in the'supply line 40a. I

In] the' apparatus contemplated bythe' present invention, it'is proposedthat, after the initial supply of water has been placed inthe boiler andthe manually controlled valve 40c closed, the further supply of waterwill be. controlled automatically to maintain the water level in theboiler within certain maximum and minimum levels, and if the watershould. recede to a point .below a predetermined level/by reason of thefailure of the automatic water control then, and

in that event, the signal 26 will be operated to warn the attendant, whocan then see that the proper supply-of water is fed to the boiler. Also,in the event of both the automatic water-control and the signal failing,or the attendant failing to heed the warning given by the signal, the,

master control unit will operate to shut off the fuel-supply upon thewater level in the boiler receding still further and approaching toonearly the danger zone or point.

The various instrumentalities will now be described in detail. vReferring to Figs. 2 and 3, the master control unit IIIII is partiallyfilled with water from the boiler through connection I02 and the upperportion of said unit is filled with steam from the boiler throughconnection I III. 1 Supported in the side wall of the master unit is abifurcated lever 4 pivoted. on a pin 4a in the valve body 8. Suspendedfrom the end of lever 4 is a float 3 supported in the body of waterwithin the master control casing. As will be apparent, recession of thewater level in the master unit chamber will cause lever 4 to be rockedand retract the valves I I, I2 and I3 from their seats l5. However, byhaving a rather neat fit between valve II and pin 9 and elongating theopening in the stem of valve I2 through which pin. 9 extends and bymaking the aperture in the stem of valve I3 still longer, the valve IIwill first be 'unseated; then valve I2 will beunseated; and, finally,valve I3 will be unseated, provided, of course, that the recession ofthe water level in chamber I progresses to a point where the lever 4will be rocked to take up all of the play allowed by the elongation ofthe slot in the stem of valve I3. At this point, it should be mentionedthat the master control unit is preferably positioned at an elevationwhere the water level therein will correspond to the water level in theboiler.

Referring to Figs. 2 and 5, a fitting 23 threaded into the port 'IBcontrolled by valve II has its outer end connected to a pipe line I50.which, in turn, leads to a chamber 4| in the casing of the water supplyvalve control mechanism 40. Chamber 4| communicates with a lower chamber42 in which there is a diaphragm 43, and connected to said diaphragm isthe stem 44 of valve 45 should recede to a point where float 3 and le-'ver 4 will be lowered suificiently to unseat valve II, steam from theupper portion of the master control unit will flow through port I6,fitting 2a and pipe line I5a, intochambers 4|, 42, of casing 40 anddeflect the diaphragm 43 downwardly with the result that valve 45 willbe unseated. The valve beingopened, water will then be supplied to theboiler through supply line 4Ila'until the level of the water in theboiler and in the master control unit rises sufliciently to move thefloat 3 and lever 4 upwardly to close valve II.

Connected to the second passage I6 in valve body 8 is a fitting 24which, in turn, is connected to a signal, such as the whistle 26, and,in the event there should be a failure in the automatic operation ofvalve 45 or should, for some cause valve I2 to be unseated, with theresult that steam issuing through this port It and fitting 24 will soundthe whistle and give warning to the attendant'of the depletion of waterin the boiler to a dangerous level.

The third passage I6 in the 'valve body 8 is providedwith a fitting 25which is connected by pipe line 25a to the valve-actuating mechanismshown in Fig; 6 for the gas or fuel supply line. This valve-actuatingmechanism comprises an upper chamber II. communicating with a lowerchamber I2 through a port 80 in which there is a check control valve 19.A diaphragm I3 in lower chamber I2 is connected to the upper extremityof the stem I4 of a valve .15 adapted to cooperate with the valve seatI5 in the fuel supply conduit 20a. In this instance, valve is normallyyieldingly held open by springs 11 but, should the water leved in theboiler recede below the point where the valve 45in the water supplyconduit will be opened, as above described,

and beyond the point where the whistle 26 will therein by reason of thepresence of check valve 19 in passage 80 and, before the valve I5 can beopened, the attendant must relieve the pressure in chamber 12. This canonly" be done manually by manipulation of a valve 18 controlling a ventopening 18a in the wall of chamber 12. In other words, once theautomatic mechanism forcutting oif the supply of fuel has been placed inoperation, the fuel line cannot be opened up automatically, but must bedone manually by the attendant who would, of course, I

ascertain that boiler conditions had been restored to normal beforeagain cutting on the fuel. I

It will be observed that fittings 23 and 25 lead ing from the valve body8' are provided. with rather minute vents 48. The purpose of the vent infitting 23 is to relieve the pressure on diaphragm 43 after the waterlevel in the boiler has risen to a point where valve II will return toits seat. Likewise, the vent in fitting 25 insures against any leakagepast valve I3 building up pressure in line 25a such as will operate thefuel cut-ofi at an improper time.

Described generally, the operation of the safety features is as follows:Assuming all three valves II, l2 and I3 to be closed, upon recession ofthe water level, control valve II in the master unit will be opened whenthe water level is lowered sounding the warning signal. If, perchance,the attendant is not present or fails to respond to the warning and thewater level continues to recede, then, when it reaches a still lowerpoint, control valve I3 of the master unit will be opened and the valve"I5 in the fuelsupply line will be closed, thus-shutting down the boilerand, as

pointed out, the boiler cannot again be placed in operation until theattendant has manually relieved the pressure in chamber 12 oi the fuel 7valve control unit. Also, as previously explained,

if the water should be replenished, upon the opening of valve 45 in thewater supply conduit, control valve II will be closed when the waterlevel rises to normal, and then the pressure on diaphragm 43 of thewater valve control mechanism will be relieved .through the vent 48 infitting 23 and the springs 41 will gradually return valve 45 to itsclosed position.

It will be appreciated that, by varying the length of the slots in thestems of the control valves in the master unit, the sequence in whichthe valves are operated or the time element involved in the successiveoperation oi the several valves, can be regulated as desired. Also,preferably, the chambers 4|, 42, in the water valve. controlmechanism 40and the chambers ll, 12, in casing ll of the mechanism for operating thefuel valve, are kept full of water to protect the diaphragms from thehigh temperature of the steam and the water added from time to time bycondensation of steam may-ultimately fill the pipe lines Ila, 25a, uptothe vents 48 in the fittings 23, 25. In this way, pressure is actuallyexerted on the diaphragms 43 and I3 by the water, the water serving totransmit the pres sures built up by the steam supplied through the portsI. in the valve body I when the control valves II, II and/or 13 areopened.

To facilitate installation and renewal of the valve seats II in valvebody I, the passages it are formed with a minor and a majorcrosssection, and the valve seat I! is positioned be-' tween these twoportions of each passage against a shoulder formed in that portion ofthe passage which is of minor cross-section. As shown in Fig. 2 eachpassage is formed with a shoulder Ila in its portion of minor,cross-section at one end of the valve seat member which abuts againstsaid shoulder. Adjacent the opposite end of the valve seat member, theinner wall of the passage of major cross-section is up-set at aplurality of circumferentially spaced points, the up-set portionsbearing against this last-mentioned end of the valve seat member toretainsaid member in the passage. However, a portion of the valve seatmember is exposed in the portion of the passage I. of minorcross-section and, by inserting a tool ll (see Fig. 8B) in the reducedportion of passage l8, and applying sumcient pressure to the valve seatmember, the up-set portions indicated at 68 will be severed or bent backand the valve seat'member pressed out of the passage. The upsetting ofthe metal for the purpose of securing the valve seatmemher in thepassage may be accomplished by the tool I, as indicated in Fig. 8A, andby merely upsetting the metal at .circumferentially spaced points, themetal can be up-set at diiterent points each time a valve seat member isrenewed. This same method of assembly and renewal may be employed inconnection with the pin which is supported in the bifurcated portion-oflever 4 and which carries the control valves II, I! and II. Forinstance, as illustrated in Figs. 7A and 7B, the arm cf the lever areprovided with open-, lugs for the pin. Opening II in one arm of thelever is oi a cross-section corresponding to thebinlbuttheopeningintheotherarmiaformed with a major cross-section It andwith a minor cross-section 34, which forms a shoulder 35 .at

the point at which these two portions merge. In assembling theseelements of the mechanism, the

pin 9 is inserted through opening 3| until its end engages againstshoulder 35in the other arm. The metal in the wall of opening 3! is thenupset at circumferentially spaced points as by a tool '36, thus securingthe plum place. To remove the pin, it is only necessary to insert a tool38 in the reduced opening 34 against the end of pin 9 which was seatedagainst shoulder," and by applying sufllcient pressure to the tool andpin, the offset portions of metal in opening 3| are severed or deflectedand the pin 9 pressed out. A new pin can then be inserted and secured inplace by upsetting fresh portions of metal in the wall of openinReferring to Figs. 3 and 4, there is shown a modified arrangement ofvalve seat members for the control valves II, I! and '3. In thisinstance, the passages iii in valve body 8 are formed with offsetportions which emerge from the upper and lower faces of the valve body.The valve seat ii. The ends of the valve members iii are also providedwith longitudinally extending vent openings of reduced cross-section,these vents indicated at 48a discharging into openings 48b in the valvebody 8. This construction eliminates the necessity of vents 48 infittings, 25, of the previously described construction. At the sametime, the valve seat members I 5 can be assembled or displaced forrenewal just the same as the valve seat members of the preferredconstruction. I

What I claim is:

1. In a safety apparatus for boilers, the combination of a fuel supplyconduit, a valve in said conduit, means for yieldingly holding saidvalve open, a compartment, a diaphragm, a protective liquid for saiddiaphragm in said compartment connections between said diaphragm andvalve, means for supplying fluid under pressure to said compartment forflexing said diaphragm and moving said valve to closed position, andmanuallyoperable means for relieving the fluid pressure on saiddiaphragm.

. 2. In a safety apparatus for boilers, the combination of a fuel supplyconduit, a valve in said conduit, means for yieldingly holding saidvalve open, a compartment, a pressure responsive means to respond topressure in said compart ment arranged to close the valve, means forsupplying fluid under pressure to said compartment to force said fluidagainst the pressure responsive means, and non-return means to preventback flow of fluid from said compartment to said supply, and manuallyoperable means to relieve the fluid'pressure in said compartment.

3. ma safety apparatus'ior' boilers, the combination of a fuel supplyconduit, a valve in said conduit, means for yieldingly holding saidvalve open, a compartment, a pressure responsive means to respond topressure in said compartment arranged to close the valve, means forsupplying fluid under pressure to said compartment to force said fluidagainst the pressure responsive means, and non-return means to preventback flow of fluid from said compartment, and manually operable means torelieve the fluid presure in said compartment and thereby open thevalve.

ALVA G. BLANCHARD;

